Tonga Power Limited says rebuilding its Ha'apai network to one that is more cyclone resistant will cost about 3.5 million US dollars.
Its chief executive, John van Brink, says about 90 percent of the network was extensively damaged by Cyclone Ian this month.
He says the company must weigh up the short and long-term electricity needs of Ha'apai.
"We certainly have an eye on how we can balance the urgency of getting supply back, against the ability to use this time where we've got to basically replace 90 per cent of our network, to rebuild it in a more resilient manner. We're going down the latter path - looking at things like putting in better poles, better wires, different designs. More like what you would see in a place like New Zealand or Australia with bundled conductors and hopefully underground connections from the roadside into the houses."
John van Brink says he's exceptionally grateful for the 1.2 million US dollars donated for the electricity network by the New Zealand government today.
He says the connections between networks and houses, which are not owned by Tonga Power but by the customer, have all been destroyed.
Mr van Brink says New Zealand's donation means the customer will not have to pay for replacing them.